stitch-ui-designer

name	stitch-ui-designer
description	Design, preview, and generate UI code using Google Stitch (via MCP). Helps developers choose the best UI by generating previews first, allowing iteration, and then exporting code.

Stitch UI Designer

This skill allows you to design high-quality user interfaces using Google Stitch.

Workflow

Follow this process to help the user design a UI:

1. Setup (First Time Only)

   • Check if the stitch server is configured in mcporter.
   • If not, configure it: mcporter config add stitch --command "npx" --args "-y stitch-mcp-auto"
   • Ensure the user is authenticated with Google Cloud (the tool may prompt for gcloud auth).

2. Generate & Preview

   • Ask for a description of the interface (e.g., "Login screen for a crypto app").
   • Use stitch.generate_screen_from_text with the prompt.
   • Important: This returns a screenId.
   • Immediately fetch the preview image using stitch.fetch_screen_image(screenId).
   • Show the image to the user. Do not fetch the code yet.

3. Iterate & Customize

   • Ask the user for feedback on the preview.
   • If changes are needed, use stitch.generate_screen_from_text again (potentially using stitch.extract_design_context from the previous screen to maintain style) or just refine the prompt.
   • Show the new preview.

4. Export Code

   • Once the user approves the design ("This looks great"), fetch the code.
   • Use stitch.fetch_screen_code(screenId).
   • Present the HTML/CSS code or save it to a file as requested.

Tools (via mcporter)

Call these using mcporter call stitch.<tool_name> <args>:

• generate_screen_from_text

  • Args: prompt (string), projectId (optional, usually auto-detected by stitch-mcp-auto)
  • Returns: screenId, name, url
  • Use this to start a design.

• fetch_screen_image

  • Args: screenId (string)
  • Returns: Image data (display this to the user).
  • Use this to show the preview.

• fetch_screen_code

  • Args: screenId (string)
  • Returns: html (string), css (string), etc.
  • Use this ONLY after user approval.

• create_project

  • Args: name (string)
  • Use if no project exists.

Tips

• Project Context: stitch-mcp-auto tries to manage the project ID automatically. If you get errors about missing project IDs, ask the user to create or select a Google Cloud project first using create_project or by setting the GOOGLE_CLOUD_PROJECT env var.
• Preview First: Always prioritize the visual preview. Generating code for a bad design wastes tokens and time.
• Stitch MCP Auto: We use stitch-mcp-auto because it handles the complex Google auth setup more gracefully than the standard package.